Jones and clinic nurses met Tuesday with Methow Valley School District officials. There are about 500 students at an elementary and junior-senior high complex in Winthrop.

Jones says about 15 percent of the Winthrop students are not immunized.

One of the students who was confirmed with pertussis on Jan. 3 attended a basketball tournament involving 17 schools on Dec. 28 and 29 at Brewster. Those schools have been advised to watch for an outbreak.

Jones says vaccinations are the best way to prevent the disease from spreading.